E1505 AC adpater problem or power jack on motherboard bad?

Hi Guys,

I have a 2 year old Inspiron E1505. I recently purchased a new battery. Since the last 2-3 days when I boot the computer the BIOS is not recognizing the AC adapter and is prompting the following message.



Once I press F1 it goes on to boot normally and runs on AC power but is not charging the battery. If I boot the laptop without a battery the laptop runs after giving the message shown above.

If (obviously with the battery connected) I unplug the AC adapter and pug it back I get the following error message.



The adapter that I am using is the original one. The following are the things I did

1) Used my adapter on a friend's E1505 - worked fine
2) Used my friend's adapter on my E1505 - worked fine
3) Measure the voltage for both the adapters and compared them - they were same

Surprisingly, after plugging in my friend's adapter, when I used my own adapter, for the first 1/2 times everything was fine and there was no error message.

These incidents make me think that the power jack soldered to the motherboard is not functioning properly. But that does not explain

1) why I can still run my laptop using AC power when no battery is connected
2) why my friend's adapter worked fine

Any advice will help.

Thanks